# Effects of excitation voltage pulse shape on the characteristics of atmospheric-pressure nanosecond discharges

## TL;DR

This study investigates how different nanosecond high-voltage pulse shapes affect atmospheric-pressure microdischarges in helium-nitrogen mixtures, revealing that pulse shape has a minor impact compared to input energy on plasma electron density.

## Contribution

It provides detailed simulation analysis of plasma dynamics under various pulse shapes, highlighting the dominant role of input energy over pulse shape effects.

## Key findings

- Electron density depends strongly on input energy.
- Pulse shape has a weak influence at constant energy.
- Simulations include VUV resonance radiation effects.

## Abstract

The characteristics of atmospheric-pressure microdischarges excited by nanosecond high-voltage pulses are investigated in helium-nitrogen mixtures, as a function of the parameters of the excitation voltage pulses. In particular, cases of single-pulse excitation, unipolar and bipolar double-pulse excitation are studied, at different pulse durations, voltage amplitudes, and delay times (for the case of double-pulse excitation). Our investigations are carried out with a particle-simulation code that also comprises the treatment of the VUV resonance radiation in the plasma. The simulations allow gaining insight into the plasma dynamics during and after the excitation pulse, the development and the decay of charged particle density profiles and fluxes. We find a strong dependence of the electron density of the plasma (measured at the end of the excitation pulse) on the electrical input energy into the plasma and a weak influence of the shape of the excitation pulse at the same input energy.